I have an almost encyclopedic knowledge of fish from the atlantic basin, specifically in and around the south east US and Carribean.
It freaks people out sometimes when I just start reciting fish facts whenever the rare occasion this comes up.
It's from me living partially on a boat as a child and tearing through books about fish while dreaming of being a marine biologist until the cold hard reality of for-profit education hit me in my early adulthood.
What are your weird topics and skills?
If I type something and then print it and re-read it I can "see the page" in my head and read off of it for a while, it fades after a couple hours. Memorized lists can last for several hours.